Thermal X-ray line emission from accreting black holes

We present model X-ray spectra of accreting black holes with hot advection-dominated accretion flows, paying attention to thermal emission lines from the hot plasma. We discuss the emission-line diagnostics that are potentially observable with the next generation of X-ray observatories, emphasizing the possibilities for determining the outer radius of the hot plasma, the presence of a wind, and the relative importance of photoionization. We present example spectra of V404 Cyg in quiescence, the Galactic center black hole Sagittarius A*, and the nucleus of M87.